1. Field of the Invention
The present invention relates generally to propulsion and specifically to a method of producing propellant-less thrust using mass fluctuation.
2. Prior Art
Aerospace propulsion technology to date has rested firmly on simple applications of the reaction principle: Creating motion by expelling propellant mass from a vehicle. A peculiar, overlooked relativistic effect makes it possible to induce large, transient rest mass fluctuations in electrical circuit components [Woodward, J. F. (1990), "A New Experimental Approach to Mach's Principle and Relativistic Graviation [sic]" Found. Phys. Lett. 3, 497-506; (1992), "A Stationary Apparent Weight Shift from a Transient Machian Mass Fluctuation" Found. Phys. Left. 5, 425-442]. An innovative implementation of this effect is to make engines that accelerate without the expulsion of any material whatsoever. This can be done because when the effect is combined with a pulsed thrust in appropriate circumstances, stationary forces can be produced [Woodward, J. F. (1992) "A Stationary Apparent Weight Shift from a Transient Machian Mass Fluctuation" Found. Phys. Lett. 5, 425-442; (1994), "Method for Transiently Altering the Mass of Objects to Facilitate their Transport of Change their Stationary Apparent Weights" U.S. Pat. No. 5,280,864, U.S. GPO, January 25; (1997b) "Mach's Principle and Impulse Engines: Toward a Viable Physics of Star Trek?" invited paper for the 1997 NASA "Breakthrough Propulsion Physics" workshop at the Lewis Research Center, August 12-14]. "Impulse engines" are achieved without any moving parts (in the conventional sense). The concepts involved are supported by experimental results already in hand. It is therefore desirable to create methods of configuring components that optimize these devices and increase their practical utility.
The transient mass fluctuation effect upon which the method of this invention (and the invention of U.S. Pat. No. 5,280,864) depends is predicated upon two essentially universally accepted assumptions. First, from general relativity theory: Inertial reaction forces in objects subjected to accelerations are produced by the interaction of the accelerated objects with a field, (produced chiefly by the most distant matter in the universe)--they are not the immediate consequence of some inherent property of the object alone. And second: Any acceptable physical theory must be locally Lorentz-invariant; that is, in sufficiently small regions of space-time special relativity theory (SRT) must obtain. Using standard techniques of physical and mathematical analysis, these assumptions lead, for a particle of matter with rest mass density .rho..sub.0 in a universe like ours (with essentially constant matter density when considered at the large scale) when accelerated by an external force, to the equation for the gravitation field potential .phi. in terms of its local sources: ##EQU1##
In this equation G is the Newtonian constant of universal gravitation, c is the vacuum speed of light, and P.sub.0 is the local rest-mass density. Details of the derivation of this field equation can be found in Woodward, 1990, 1992, 1995, 1997a and 1997b [Woodward, J. F. (1990), "A New Experimental Approach to Mach's Principle and Relativistic Graviation [sic]" Found. Phys. Lett. 3 497-506; (1992), "A Stationary Apparent Weight Shift from a Transient Machian Mass Fluctuation" Found. Phys. Lett. 5, 425-442; (1995), "Making the Universe Safe for Historians: Time Travel and the Laws of Physics" Found. Phys. Lett. 8, 1-39; (1997a), "Twists of Fate: Can We Make Traversable Wormholes in Spacetime?" Found. Phys. Lett. 10, 153-181; (1997b), "Mach's Principle and Impulse Engines: Toward a Viable Physics of Star Trek?" invited paper for the 1997 NASA "Breakthrough Propulsion Physics" workshop at the Lewis Research Center, August 12-14. The equation is at least approximately valid for all relativistic theories of gravity.
In stationary circumstances, where all terms involving time derivatives vanish, the field equation above reduces to Poisson's equation, and the solution for .phi. is just the sum of the contributions to the potential due to all of the matter in the causally connected part of the universe, that is, within the particle horizon. This turns out to be roughly GM/R, where M is the mass of the universe and R is about c times the age of the universe. Using reasonable values for M and R, GM/R is about c.sup.2. In the time-dependent case we must take account of the terms involving time derivatives on the right hand side of this equation. Note that these terms either are, or in some circumstances can become, negative. It is the fact that these terms can also be made very large in practicable devices with extant technology that makes them of interest for rapid space time transport, the chief area of application of impulse engines.
Since the predicted mass shift is transient, large effects can only be produced in very rapidly changing proper matter (or energy) densities produced by accelerating matter. From the point of view of detection of the effect, this means that the duration of any substantial effect will be so short that it cannot be measured by usual weighing techniques. If however, we drive a periodic mass fluctuation and couple it to a synchronous pulsed thrust, it is possible to produce a measurable stationary effect [Woodward, J. F. (1992), "A Stationary Apparent Weight Shift from a Transient Machian Mass Fluctuation" Found. Phys. Lett. 5, 425-442; (1994), "Method for Transiently Altering the Mass of Objects to Facilitate their Transport of Change their Stationary Apparent Weights" U.S. Pat. No. 5,280,864, U.S. GPO, January 25 ; (1996b), "A Laboratory Test of Mach's Principle and Strong-Field Relativistic Gravity" Found. Phys. Lett. 9, 425-442]. Consider, for example, the generic apparatus shown in FIG. 1 in which a stationary net force is produced by generating a periodic mass fluctuation in a capacitor array (CA) and synchronously causing the length of a piezoelectric force transducer (PZT) to oscillate so that the inertial reaction force of the accelerating CA on the PZT and enclosure (E) is added to the weight of the assembly which is detected by the depression of the steel diaphragm (D) measured by the position sensor (S), all of which is located in a thick walled aluminum case c mounted on a seismically isolated table. Here a mass fluctuation is produced in the CA by driving them with an AC voltage. While the mass of the CA fluctuates, the PZT causes a synchronous, oscillatory acceleration of the CA. The inertial reaction force F felt by the PZT [and the enclosure (E) in which it is mounted] will be the product of the instantaneous mass of the CA times the acceleration of the CA induced by the PZT. If the mass fluctuation and acceleration are both sinusoidal and phase-locked at the same frequency, then their product yields a phase-dependent, time-independent term--a stationary force.
The magnitude of this stationary force is calculated in detail in Woodward, 1992, 1994, 1996b and 1997b. If we drive an oscillation in a PZT arranged like that in FIG. 1 with amplitude .delta.l.sub.0 at a frequency of 2.omega., assume that the mass of the CA is small compared to that of the enclosure E so that the excursion of the PZT accelerates the CA only and allow for a phase angle .delta. between .delta.m.sub.0 and .delta.l.sub.0, the time averaged inertial reaction force &lt;F&gt;=&lt;.delta.m(t)a(t)&gt; detected by the sensor S (as a change in equilibrium position due to the change in the force on the diaphragm spring D) is: EQU &lt;F&gt;=-2.omega..sup.2 .delta.1.sub.0 .delta.m.sub.0 cos .crclbar..
.delta.m.sub.0 is the amplitude of the mass fluctuation induced when a sinusoidal voltage of angular frequency .omega. is applied to the capacitors. That is, the application of the voltage to the capacitors leads to an instantaneous power P=P.sub.0 sin(2.omega.t) in the circuit, leading to a mass fluctuation: EQU .delta.m(t)=(.phi..omega.P.sub.0 /2nG.rho..sub.0 c.sup.4)cos(2.omega.t)=.delta.m.sub.0 cos(2wt).
The reality of the effect involved here and its implementation in producing stationary forces has been demonstrated in laboratory experiments [Woodward, 1996b, 1997b and below]. In this work .delta.l.sub.0 was a few angstroms (easily achieved with normal PZTs). When P.sub.0 .congruent.250 watts, .omega..congruent.8.8.times.10.sup.4 (14 kHz), and cos .crclbar..congruent..+-.1, forces on the order of tens of dynes or more were produced in the apparatus. In practice one takes the difference between runs adjusted so that cos .crclbar..congruent.-1. Results obtained at 14 kHz with a device of this sort are shown in FIG. 2. FIG. 2 displays the averaged results obtained with a device like that is shown in FIG. 1 where a capacitor array with a total capacitance of 0.02 microfarads mounted between piezoelectric transducers that produce an excursion of several hundred Angstroms was run at a power frequency of 28 kiloHertz during the time interval 7 to 12 seconds out of the 20 second data acquisition interval, resulting in a net force of about ninety five milligrams (dynes) when the data acquired for relative phases 180 degrees apart were differenced. The traces for the averages of the two phase settings are those that show large changes in the active interval. The heavy trace is that for 0 degrees of phase and the light trace that for 180 degrees of phase. The difference of these traces is the heavy trace that roughly vertically bisects the plot. These results were obtained with the case evacuated to a pressure of less than 15 mm of Hg. At 5 seconds into a data acquisition cycle the CA is powered up. In the 7 to 12 second interval both the CA and PZT are active. And at 14 seconds the CA is switched off. Typically one to two dozen such cycles are taken in a run with the phase .crclbar. switched back and forth by 180 degrees in alternating cycles of data. When the averages for the two phases are differenced, they produce the displayed differential weight shift. It is forces of the sort just described that can be used to make impulse engines.